<template>
  <view>
    <!-- 搜索框 -->
    <my-search @click="goSearch"></my-search>
    <view class="scroll-view-container">
      <!-- 左侧的滚动视图区域 -->
      <scroll-view class="left-scroll-view" scroll-y :style="{height: wh + 'px'}">
        <block v-for="(item, i) in cateList" :key="i">
          <view :class="['left-scroll-view-item', i === active ? 'active' : '']" @click="activeChanged(i)">{{item.cat_name}}</view>
        </block>
      </scroll-view>
      <!-- 右侧的滚动视图区域 -->
      <scroll-view class="right-scroll-view" scroll-y :style="{height: wh + 'px'}" :scroll-top="scrollTop">
         <view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
           <view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
               <!-- 动态渲染三级分类的列表数据 -->
               <view class="cate-lv3-list" v-for="(item3, i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
                 <!-- 三级分类 Item 项 -->
                 <view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3">
                   <!-- 图片 -->
                   <image :src="item3.cat_icon"></image>
                   <!-- 文本 -->
                   <text>{{item3.cat_name}}</text>
                 </view>
               </view>
         </view>
      </scroll-view>
    </view>
  </view>
</template>

<script>
 import badgeMix from '@/mixins/tabber-badge.js'
 export default {
    mixins: [badgeMix],
    data() {
      return {
        wh: 0,
        // 分类列表数据
        cateList: [],
        active: 0, // 当前选中项的索引
        cateLevel2: [], // 二级分类列表
        scrollTop: 0 // 滚动条距离顶部的距离
      };
    },
    onLoad() {
      const sysInfo = uni.getSystemInfoSync()
      this.wh = sysInfo.windowHeight - 50
      this.getCateList()
    },
    methods: {
      // 获取分类列表数据
     async getCateList() {
        const { data: res } = await uni.$http.get('/api/public/v1/categories')
        if (res.meta.status !== 200) return uni.$showMsg()
        this.cateList = res.message  
        // 为二级分类赋值
        this.cateLevel2 = res.message[0].children
      },
      // 左侧点击索引改变
      activeChanged(i) {
        this.active = i
        // 为二级分类列表重新赋值
        this.cateLevel2 = this.cateList[i].children
        this.scrollTop = this.scrollTop === 0 ? 1 : 0
      },
      // 跳转到搜索页面
      goSearch() {
        uni.navigateTo({
          url: '/subpkg/search/search'
        })
      },
      // 点击三级分类项跳转到商品列表页面
      gotoGoodsList(item3) {
        uni.navigateTo({
          url: '../../subpkg/goods_list/goods_list?cid=' + item3.cat_id
        })
      }
    },
 
  }
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;

  .left-scroll-view {
    width: 120px;

    .left-scroll-view-item {
      line-height: 60px;
      background-color: #f7f7f7;
      text-align: center;
      font-size: 12px;

      // 激活项的样式
      &.active {
        background-color: #ffffff;
        position: relative;

        // 渲染激活项左侧的红色指示边线
        &::before {
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #c00000;
          position: absolute;
          left: 0;
          top: 50%;
          transform: translateY(-50%);
        }
      }
    }
  }
  .cate-lv2-title {
    font-size: 12px;
    font-weight: bold;
    text-align: center;
    padding: 15px 0;
  }
  .cate-lv3-list {
    display: flex;
    flex-wrap: wrap;
  
    .cate-lv3-item {
      width: 33.33%;
      margin-bottom: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
  
      image {
        width: 60px;
        height: 60px;
      }
  
      text {
        font-size: 12px;
      }
    }
  }
}
</style>
